Wetpixel SLR video light review

by Adam HanlonFriday, May 18th, 2012

Comparative review: Mangrove VC-4L6 vs. Keldan LUNA 4V.

SLR video lights head-to-head.

Since the beginning, lighting subjects underwater has presented underwater image makers with a series of challenges. Still photographers were able to solve these problems relatively quickly, initially by simply housing land flashes, and then with purpose designed underwater units. The power requirements to produce a high intensity flash for a very brief period were relatively easy to satisfy. However, underwater filmmaking requires lights in order to restore color as does still imagery, but needs these lights to be continuos for the period that the camera is running.

This has lead to a range of solutions, including using waterproof lights powered from the shore or surface via an umbilical. As light and battery technology has improved, so the size, power and portability of lighting systems has also improved. High Intensity Discharge bulbs, introduced in the late 1990s, meant that video lights with sufficient power and longevity were possible in units that were portable enough to be carried around, although these typically required a separate (umbilical) battery pack to achieve significant burn time.

The advent of LED lighting over the past 4 to 5 years, and the steep increase in both the LED’s performance and the battery technology required to drive them, has resulted in a wide range of video lighting in very compact units. Performance in terms of output power and longevity is possible now in units that are a fraction of the size that comparable units were even a few years ago.

This has coincided with a growth in both the quality and performance of video that can be captured on SLR cameras. However, these require a great deal of light to provide good results underwater. SLR shooters also want the convenience of being able to shoot both stills and video on the same dive, and to travel with both strobes and video lights. The latter has become especially difficult with increasingly draconian weight limits for airline travel.

The purpose of this review was to gather together new video lights that represent options for the SLR video shooter. It is not an overall video light review, and there are many other very capable lights available in the market. The three originally selected were the Light & Motion SOLA 4000, the Mangrove VC-4L6 and the Keldan LUNA 4V. All three of these have 4,000 lumen outputs, are self-contained (batteries are integrated into the canister not separate) and are small and light enough for the SLR video shooter.

Unfortunately, Light & Motion were unable to supply test units for this review, although I hope to be able to provide a separate review she they have units available.

An early SOLA 4000, unfortunately we were unable to include them in the review.

Mangrove VC-4L6

Spanish manufacturer Aditech released their Mangrove VC-4L6 in 2011. This light forms a part of a modular system, and the lights can be equipped with a variety of different handles, mounting systems and umbilical power packs. The test units had 1” ball mounts attached to the “T” plates on the lights’ bodies.

The light features a solid-state LED module array emitting a quoted 4320 lumens.

It has two output levels, 100% and 60%, controllable via a magnetic switch.

The battery pack and switch assembly are removed from the torch body for charging, with a charging port on the side of the battery.

The Keldan LUNA 4V has a quoted output of 4000 lumens, with this measurement being taken outside of the lens.

Its output can be controlled via a 5 stage magnetic switch.

Integrated into the battery pack is an 8 stage battery charge indicator, which shows remaining charge in the battery during use or charging. The battery pack is removed from the torch body for charging with a charging port in the top of the battery.

It is attached via a YS mount and handles are available to convert it into a dive light.

Manufacturer’s specifications are as follows:

Power consumption: 11-45W

Luminous Flux (Lumen): 4000 lm.

Beam angle: 80° cov­er­age in wa­ter (110° in air).

Color temperature: 5000° Kelvin.

Output levels: 5 settings from 11 - 45 Watts

Powered by: Li-Ion bat­tery ­pack 14.8V - 2.9Ah

Burn time: 50min (100%) / 200 min. (11 Watt output)

Charging time: 3:57 h.

Dimensions:

Diameter: 72mm

Length: 160mm

Weight: 700g (land) / 220g (water)

Price: £1049.00 ($1669.05/€1313.10)

In use.

The testing that I carried out aimed to use the lights in very similar conditions. In total, the tests have involved about 20 dives. Some dives were done with both sets of lights, and they were alternated, and some were carried out in close succession to each other. In all instances, the filming was done on a Nikon D7000 with a Sigma 8-16mm rectilinear lens. I also used a Nauticam NA-DP4 with a SmallHD 4.3” monitor.

No color correction or post capture processing has been carried out except the actual edit.

To my eye, the Mangrove lights have a warmer color temperature. It would appear that they also have a slightly wider beam angle. Both torches have very even beams with no hot spots at all.

The second test was to rate the lights in terms of output. I simply shined the lights at the airplane’s fuselage while backing away. The Keldans seem to be a little brighter.

I burn tested both sets of light four times, at 100% power output with the lights immersed. The average for the Keldan lights was 53 minutes, and the Mangroves 61 minutes, which ties into the manufacturer’s quoted specs in both cases. Recharge times were somewhat different from each other, with the Mangroves taking 5 hours 35 minutes (from “empty”) and the Keldans taking 4 hours 2 minutes. Again these are an average over 4 cycles. Keldan’s battery pack does have an integrated charge level indicator that gives an 8 step view of battery capacity in both charge and discharge modes. Mangrove’s does give an audible (mosquito) warning when the battery is nearly discharged, but has no “in use” indicator.

Practically, this means that in each case, if you plan to do a significant amount of filming over more than one dive in a day, you will need to purchase additional battery packs. It is worth factoring this in to your budget.

From Left: Keldan battery, Mangrove battery.

The 5 step adjustment on the Keldan lights gives a very precise control over the amount of light needed. This is of benefit especially in bright conditions, when the lights are simply adding a color correction back in to compensate for the spectrum lost as the light passes through the water. The Mangroves 60% adjustment was still a bit bright at times.

An important consideration is the issue of size and weight. Performance underwater is, as the tests show, similar. SLR shooters may well want to switch from video to still during a dive, and hence carry both strobes and lights attached to their housings. Travel also places increasingly severe weight restrictions on us, and it is here that the Keldans have a significant edge as they are just under half the weight of the Mangroves. Whilst it may be possible to attach both the Mangrove lights and strobes to your strobe arms, it will be pretty awkward!

The size argument can be reversed in terms of price. The Mangrove represents excellent value when compared to the Keldan. I guess the adage in this instance is that less (in size and weight) costs more.

I am very aware that other options may well exist in video lighting with around 4000 lumens of output, and that this review is not exhaustive. Wetpixel would welcome the opportunity to review other models that may be on, or are coming on, to the market. Similarly, although the focus of this review has been using these lights with SLR cameras, the findings very much still apply to those with “conventional” video cams

Both sets of lights represent fantastic examples of how LED and battery technology has revolutionized underwater lighting. Both show significant improvements in terms of output and longevity. The decision between them now rests on whether the user values price or size as a priority.

FTC disclosure Both sets of lights were loaned to the reviewer for the review. Many thanks to Andy Fenn of Blue Orb for the loan of the Keldan LUNA 4Vs and to Juan Sentís Panes of Aditech/Mangrove for the loan of the Mangrove VC-4L6 lights.

The mangrove gets almost 5 times the burn time at the 60% setting. Can that be correct?
BartPosted by Glasseye Snapper on 2012-05-20 10:48:06